Crystal (xtal) oscillator with high interference immunity

ABSTRACT

Systems and methods are provided for generating reference signals with high interference immunity. A signal source may generate reference signals having a particular reference frequency based on characteristics of the source of the reference signals, for use in driving at least one component in a system. One or more processing may then process the generated reference signals, based on particular frequency positions relative to the particular reference frequency and other operations and/or components of the system. The processing may include filtering at the particular frequency positions. The particular frequency positions may correspond to the harmonics positions of the particular reference frequency. The signal source may be a crystal oscillator.

CLAIM OF PRIORITY

This patent application is a continuation of U.S. Provisional patentapplication Ser. No. 15/177,045, filed on Jun. 8, 2016, which makesreference to, claims priority to and claims benefit from U.S.Provisional Patent Application Ser. No. 62/172,579, filed on Jun. 8,2015. Each of the above-identified applications is hereby incorporatedherein by reference in its entirety.

TECHNICAL FIELD

Aspects of the present disclosure relate to signal processing. Morespecifically, various implementations of the present disclosure relateto crystal (xtal) oscillator with high interference immunity.

BACKGROUND

Conventional approaches for utilizing crystal (xtal) oscillators (e.g.,to provide clocking or other periodic signals) in electronic systems,may be costly, cumbersome, or inefficient. Further limitations anddisadvantages of conventional and traditional approaches will becomeapparent to one of skill in the art, through comparison of such systemswith some aspects of the present disclosure as set forth in theremainder of the present application with reference to the drawings.

BRIEF SUMMARY

System and methods are provided for crystal (xtal) oscillator with highinterference immunity, substantially as shown in and/or described inconnection with at least one of the figures, as set forth morecompletely in the claims.

These and other advantages, aspects and novel features of the presentdisclosure, as well as details of an illustrated embodiment thereof,will be more fully understood from the following description anddrawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates an example electronic system that utilizes crystal(xtal) oscillators.

FIG. 2 illustrates an example CMOS radio frequency (RF) transceiver thatutilizes a crystal (xtal) oscillator.

FIG. 3A illustrates an example crystal (xtal) oscillator, in which highfrequency interference may occur.

FIG. 3B shows frequency charts for an example use scenario in thecrystal (xtal) oscillator of FIG. 3A.

FIG. 4A illustrates an example crystal (xtal) oscillator with highfrequency interference immunity.

FIG. 4B shows frequency charts for an example use scenario in thecrystal (xtal) oscillator of FIG. 4A.

FIG. 5 illustrates a flowchart of an example process for handlingcrystal (xtal) oscillator with high interference immunity.

DETAILED DESCRIPTION OF THE INVENTION

As utilized herein the terms “circuits” and “circuitry” refer tophysical electronic components (e.g., hardware) and any software and/orfirmware (“code”) which may configure the hardware, be executed by thehardware, and or otherwise be associated with the hardware. As usedherein, for example, a particular processor and memory may comprise afirst “circuit” when executing a first one or more lines of code and maycomprise a second “circuit” when executing a second one or more lines ofcode. As utilized herein, “and/or” means any one or more of the items inthe list joined by “and/or”. As an example, “x and/or y” means anyelement of the three-element set {(x), (y), (x, y)}. In other words, “xand/or y” means “one or both of x and y.” As another example, “x, y,and/or z” means any element of the seven-element set {(x), (y), (z), (x,y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and/or z” means“one or more of x, y, and z.” As utilized herein, the term “exemplary”means serving as a non-limiting example, instance, or illustration. Asutilized herein, the terms “for example” and “e.g.” set off lists of oneor more non-limiting examples, instances, or illustrations. As utilizedherein, circuitry is “operable” to perform a function whenever thecircuitry comprises the necessary hardware and code (if any isnecessary) to perform the function, regardless of whether performance ofthe function is disabled or not enabled (e.g., by a user-configurablesetting, factory trim, etc.).

FIG. 1 illustrates an example electronic system that utilizes crystal(xtal) oscillators. Shown in FIG. 1 is an electronic system 100.

The electronic system 100 may comprise suitable circuitry forimplementing various aspects of the present disclosure. The electronicsystem 100 may be configured to support performing, executing or runningvarious operations, functions, applications and/or services. Theelectronic system 100 may be used, for example, in executing computerprograms, playing video and/or audio content, gaming, performingcommunication applications or services (e.g., Internet access and/orbrowsing, email, text messaging, chatting and/or voice callingservices), providing networking services (e.g., WiFi hotspot, Bluetoothpiconet, Ethernet networking, cable or satellite systems, and/or active4G/3G/femtocell data channels), or the like.

In some instances, the electronic system 100 may enable and/or supportcommunication of data. In this regard, the electronic system 100 mayneed to communicate with other systems (local or remote), such as duringexecuting, running, and/or performing of operations, functions,applications and/or services supported by the electronic system 100. Forexample, the electronic system 100 may be configured to support (e.g.,using suitable dedicated communication components or subsystems) use ofwired and/or wireless connections/interfaces, which may be configured inaccordance with one or more supported wireless and/or wired protocols orstandards, to facilitate transmission and/or reception of signals(carrying data) to and/or from the electronic system 100. In thisregard, the electronic system 100 may be operable to process transmittedand/or received signals in accordance with applicable wired or wirelessprotocols.

Examples of wireless standards, protocols, and/or interfaces that may besupported and/or used by the electronic system 100 may comprise wirelesspersonal area network (WPAN) protocols, such as Bluetooth (IEEE 802.15);near field communication (NFC) standards; wireless local area network(WLAN) protocols, such as WiFi (IEEE 802.11); cellular standards, suchas 2G/2G+(e.g., GSM/GPRS/EDGE, and IS-95 or cdmaOne) and/or 2G/2G+(e.g.,CDMA2000, UMTS, and HSPA); 4G standards, such as WiMAX (IEEE 802.16) andLTE; Ultra-Wideband (UWB), and/or the like.

Examples of wired standards, protocols, and/or interfaces that may besupported and/or used by the electronic system 100 may comprise Ethernet(IEEE 802.3), Fiber Distributed Data Interface (FDDI), IntegratedServices Digital Network (ISDN), cable television and/or internet accessstandards (e.g., ATSC, DVB-C, DOCSIS, etc.), in-home distributionstandards such as Multimedia over Coax Alliance (MoCA), and UniversalSerial Bus (USB) based interfaces.

Examples of signal processing operations that may be performed by theelectronic system 100 comprise, for example, filtering, amplification,analog-to-digital conversion and/or digital-to-analog conversion,up-conversion/down-conversion (e.g., between different frequency bands),encoding/decoding, encryption/decryption, and/ormodulation/demodulation.

In some instances, the electronic system 100 may be configured to enableor support input/output operations, such as to allow user interactionsthat may be needed for controlling the electronic system 100 oroperations thereof (e.g., to allow operators to provide input orcommands for controlling location specific marketing, or obtain outputor feedback pertaining to it). In this regard, the electronic system 100may comprise components or subsystems for enabling interactions with auser (e.g., end-user or installer), so as to obtain user input and/or toprovide user output.

In some instances, the electronic system 100 may enable or supportinput/output operations, such as to allow providing output to and/orobtaining input from user(s) of the electronic system 100. In thisregard, the electronic system 100 may comprise components or subsystemsfor enabling obtaining user input and/or to provide output to the user.For example, the electronic system 100 may enable or supportinput/output operations for allowing user interactions which may beneeded for controlling the electronic system 100 or operations thereof(e.g., allowing operators to provide input or commands for controllingcertain functions or components, to output or provide feedbackpertaining, etc.). The electronic system 100 may also be operable tosupport input and/or output of multimedia data. For example, theelectronic system 100 may enable or support generating, processing,and/or outputting of video and/or acoustic signals, such as via suitableoutput devices or components (e.g., displays, loudspeakers, etc.). Theoutput signals may be generated based on content, which may be indigital form (e.g., digitally formatted music or the like). Similarly,the electronic system 100 may enable or support capturing and processingof video and/or acoustic signals, such as via suitable input devices orcomponents (e.g., cameras, microphones, etc.), to generate correspondingdata. The corresponding data may be in digital form (e.g., digitallyformatted music, other audio, video, or the like).

The electronic system 100 may be a stationary system (i.e. beinginstalled at, and/or configured for use only in particular location). Inother instances, however, the electronic system 100 may be a mobiledevice—i.e. intended for use on the move and/or at different locations.In this regard, the electronic system 100 may be designed and/orconfigured (e.g., as handheld device) to allow for ease of movement,such as to allow it to be readily moved while being held by the user asthe user moves, and the electronic system 100 may be configured toperform at least some of the operations, functions, applications and/orservices supported on the move.

Examples of electronic systems may include handheld electronic devices(e.g., cellular phones, smartphones, tablets, etc.), computers (e.g.,laptops, desktops, servers, etc.), dedicated media devices (e.g.,televisions, game consoles, or portable media players, etc.), set-topboxes (STBs) or other similar receiver systems, and the like. Thedisclosure, however, is not limited to any particular type of electronicsystem.

In operation, the electronic system 100 may be operable to performvarious operations, functions, applications and/or services. Further,the electronic system 100 may comprise suitable components (e.g.,circuitry) for enabling and/or supporting the operations, functions,applications and/or services provided thereby. For example, in someinstances, electronic system 100 may be operable to communicate (sendand/or receive) data, and to process the communicated data.Communication of data, whether over wired or wireless interfaces, maytypically comprise transmitting and/or receiving signals that arecommunicated over wireless and/or wired connections. For example, analogradio frequency (RF) signals may be used to carry data (e.g., content),with the data being embedded into the analog signals in accordance witha particular analog or digital modulation scheme. For analogcommunications, data is transferred using continuously varying analogsignals, and for digital communications, the analog signals are used totransfer discrete messages in accordance with a particulardigitalization scheme. Thus, handling of various operations, functions,applications and/or services in the electronic system 100 may typicallyrequire performing various signal processing operations, to facilitatereception and/or transmission of signals, generation of signals,extracting of data from (or embedding into) signals, and the like. Theelectronic system 100 may comprise various components for enabling RFbased communications. For example, the electronic system 100 maycomprise one or more RF transceivers 120. In this regard, each RFtransceiver 120 may comprise suitable circuitry for transmitting andreceiving RF signals (e.g., over the air or over wired connectors), andfor performing at least some of the processing functions required tofacilitate such transmission and/or reception.

In some instances, at least some of the operations performed in theelectronic system 100 (and/or the components used in providing suchoperations) may require particular signals (e.g., control) which mayneed to be generated within the electronic system 100. For example, someof the components or subsystems of the electronic system 100 may requireclock (or other similar periodic) signals, which may be utilized incontrolling operations (or clocking/timing thereof) of variouscomponents or subsystems in the electronic system 100. Thus, theelectronic system 100 may be configured to generate the clock (or otherperiodic) signals, such as by incorporating dedicated components, whichmay be utilized in generating (or enabling the generation of) thesesignals. For example, the electronic system 100 may comprise one or morecrystal (xtal) oscillator 110. In this regard, each crystal oscillator110 may comprise suitable circuitry for creating an electrical signalwith a precise frequency based on mechanical resonance of a vibratingcrystal (e.g., a piezoelectric material). The frequency of theelectrical signal may be used to keep track of time, such as to enableproviding a precise and stable basis for triggering the needed clock orother signals in the electronic system 100.

Various architectures and/or designs may be used in implementing crystal(xtal) oscillators and the use thereof in electronic systems. In thisregard, in its most basic implementation, a crystal oscillator comprisesa crystal (e.g., quartz crystal) which may be specifically selectedbased on a particular resonant frequency associated therewith, as wellas some circuitry for generating electronic signals based on themechanical resonance of the crystal.

Various issues may exist with conventional approaches for utilizingcrystal (xtal) oscillators in electronic systems, however. As notedabove, crystal (xtal) oscillators may be utilized in generating periodicsignals (e.g., for clock signals, etc.), based on resonant frequency ofa crystal, for electronic systems. The crystal (xtal) oscillators and/orfunctions thereof, however, may be affected by other components and/orfunctions in the electronic systems. In some instances, the operation ofcrystal (xtal) oscillators may suffer from and/or be affected by, forexample, interference, which may be introduced due to functions ofvarious sub-components the crystal (xtal) oscillators and/or due tooperations or functions of other components in the system (e.g.,transceivers, such as the transceiver 110 in the electronic system 100).

Accordingly, in various implementations in accordance with the presentdisclosure, crystal (xtal) oscillators may be designed and/or configuredto specifically account for and mitigate particular adverse conditions,such as interference, as described in more detail below.

FIG. 2 illustrates an example CMOS radio frequency (RF) transceiver thatutilizes crystal (xtal) oscillator. Shown in FIG. 2 is an electronicarrangement 200, which may be included in an electronic system (e.g.,the electronic system 100 of FIG. 1).

The electronic arrangement 200 may comprise suitable circuitry used inproviding and/or performing particular operations and/or functions inthe electronic system. The electronic arrangement 200 may be operable toprovide and/or perform, for example, RF transmit/receive functions,and/or clocking generation required therefor. For example, as shown inthe example implementation depicted in FIG. 2, the electronicarrangement 200 may comprise a crystal (xtal) oscillator 210, acomplementary metal-oxide semiconductor (CMOS) radio frequency (RF)transceiver system-on-chip (SoC) 220, and one or more RF front-ends(e.g., 230 ₁-230 ₄). In this regard, the electronic arrangement 200 mayrepresent an example implementation of at least a portion of thecombination of the crystal oscillator 110 and the RF transceiver 120 ofFIG. 1.

The xtal oscillator 210 may comprise suitable circuitry for creatingelectrical signals with a particular precise frequency (e.g., f_xtal)based on a crystal included therein (e.g., based on mechanical resonanceof the crystal). The signal generated by the xtal oscillator 210 (or,specifically, the frequency f_xtal thereof) may be used to keep track oftime, such as to enable providing a precise and stable basis fortriggering the needed clock or other signals in the electronicarrangement 200.

The complementary metal-oxide semiconductor (CMOS) radio frequency (RF)transceiver system-on-chip (SoC) 220 may comprise circuitry that handlestransmission and reception of RF signals (e.g., over the air or overwired connectors), which may comprise performing at least some of theprocessing functions required to facilitate such transmission and/orreception. The transceiver CMOS RF transceiver SoC 220 may specificallybe implemented using CMOS based, system-on-chip architecture—that is,using a complementary metal-oxide semiconductor based integrated circuit(IC) that integrates all components of the transceiver (including, e.g.,digital, analog, radio-frequency related components and functions) on asingle chip (substrate).

In some instances, the CMOS RF transceiver SoC 220 may be configured tosupport multiple RF based communications—e.g., via the (over-the-air) RFfront-ends 230 ₁-230 ₄, and via one or more transmission lines 240(e.g., wired-based) associated with a particular high speed digitalinterface (e.g., serial link).

In operation, the electronic arrangement 200 may support RFcommunications, such as via the RF front-ends 230 ₁-230 ₄ and/or thetransmission line(s) 240. In this regard, at least some of theoperations performed in the electronic arrangement 200 (e.g., RFcommunication) and/or the components used in providing such operations(e.g., the CMOS RF transceiver SoC 220) may require clock (or othersimilar periodic) signals, which may be generated using (or based onsignals generated by) the xtal oscillator 210. In some instances,however, the operation of xtal oscillator 210 may be subject tointerference, which may be introduced within the xtal oscillator 210itself (e.g., due to functions of various sub-components thereof) and/ordue to operations or functions of other components (e.g., thetransceiver 220).

For example, the xtal oscillator 210 may have to coexist with multiplehigh power RF communications (the combination of transceiver 200 the RFfront-ends 230 ₁-230 ₄) as well as with communication via the high speeddigital interface, at both the chip and the board level, resulting ininterference. In this regard, certain functions may be performed orapplied during transmission on the chip, which may affect (or evencorrupt) the reference signals being outputted by the xtal oscillator(and cause, in some instances, SNR degradation from the transmitted)signal. This may be because these functions may generate signals withsufficiently high energy and are sufficiently close enough to thereference signals (or harmonics thereof) generated by the xtaloscillator 210 to cause interference. For example, a PA (poweramplifier), which may output a modulated signal having a higherfrequency, may be used in the transmitter(s), the associated energy mayget coupled to the crystal oscillator, and if it gets close to theharmonics of the crystal, interference may be introduced. This isexplained in more detail with respect to FIGS. 3A and 3B.

FIG. 3A illustrates an example crystal (xtal) oscillator, in which highfrequency interference may occur. Shown in FIG. 3A is a crystal (xtal)oscillator 300.

The xtal oscillator 300 may comprise suitable circuitry for creatingreference signals with a particular frequency (e.g., f_xtal) based on acrystal (e.g., based on mechanical resonance of the crystal). The xtaloscillator 300 may correspond to the xtal oscillator 210 of FIG. 2,representing a particular example implementation thereof. In thisregard, as shown in FIG. 3A, the xtal oscillator 300 may comprise a xtalcore 310 (which comprises the crystal itself as well as circuitryoperable to generate electrical signals based on the crystal), and axtal buffer 320, which may comprise suitable circuitry forpost-processing the initial signal generated (via the xtal core 310)based on the crystal. The xtal buffer 320 may be configured to, forexample, buffer and digitize the reference signal—that is, convert theanalog signals generated based on resonance of the crystal into digitalsignals that can be used as, e.g., clock signals.

As noted with respect to FIG. 2, in some instances functions performedin the system or components that are coupled to the xtal oscillator mayintroduce interference. For example, the PA (typically having amodulated signal with high frequency and high energy) may affect thextal oscillator as the PA energy may leak into the crystal node(particularly the xtal core 310). Such transmission signals (e.g., RF1,RF2, RF3, etc.) may, in some instances, be close to the harmonics of thecrystal's reference signal, as further illustrated in FIG. 3B, whichshows frequency charts for an example use scenario in the crystal (xtal)oscillator of FIG. 3A.

In this regard, the reference signal outputted by the xtal core 310, atpoint A (as marked in FIG. 3A), may include both the crystal-basedsignal (at f_xtal) as well as the high power transmission-basedinterference signals at the harmonics positions (e.g., N1*f_xtal,N2*f_xtal, N3*f_xtal, etc.), as illustrated in frequency chart 311 inFIG. 3B. The mixed signal then may go through and be processed by thextal buffer 320. The xtal buffer 320 may be a nonlinear circuit. As aresult, the high power interference at the multiple harmonics of thextal oscillator signal's frequency (f_xtal) becomes in-band noise—e.g.,due to the squaring action performed by the xtal buffer 320. In thisregard, the output signal of the xtal buffer 320 (e.g., square clocksignal), at point B (as marked in FIG. 3A) may comprise a mix of thecrystal-based signal and strong interference signals at the xtaloscillator signal's frequency (f_xtal), as well as at certain harmonicspositions (e.g., N3*f_xtal, N5*f_xtal, etc.), as illustrated infrequency chart 321 in FIG. 3B.

Accordingly, in various implementations in accordance with the presentdisclosure, measures may be taken to account for and mitigate (e.g.,reduce or even eliminate) the effects of any interference signals thatmay otherwise degrade the performance of crystal oscillators. Forexample, this may be done by processing the reference signals within thextal oscillator to clean them up from the interference signals (oreffects thereof)—e.g., attenuate the interference signals out. Thereference signal generated and outputted by the crystal core may beprocessed, for example, to remove the interference signals beforefurther processing, such as via the crystal buffer, wherecharacteristics thereof (e.g., nonlinearity) may particularly worsenperformance of the oscillator. An example implementation is describedwith respect to FIGS. 4A and 4B.

FIG. 4A illustrates an example crystal (xtal) oscillator with highfrequency interference immunity. Shown in FIG. 4A is a crystal (xtal)oscillator 400.

The xtal oscillator 400 may be substantially similar the xtal oscillator300, operating in substantially similar manner, for example. Inparticular, the xtal oscillator 400 may also comprise a xtal core 410and a xtal buffer 420, which may be similar to the xtal core 310 and axtal buffer 320. The xtal oscillator 400 may additionally comprise,however, a xtal filter 430. In this regard, the xtal filter 430 maycomprise suitable circuitry for filtering output portions of the outputsignals where interference may be introduced.

For example, the xtal filter 430 may be a low-pass filter configured topass the signal at the xtal oscillator signal's frequency (f_xtal),while filtering out higher frequencies, including the harmonics'frequencies (e.g., N1*f_xtal, N2*f_xtal, N3*f_xtal, etc.) in particular,for example. The xtal filter 430 may be implemented, for example (asshown in the example implementation depicted in FIG. 4A), as aresistor-capacitor (RC) circuit (arranged in the particular manner shownin FIG. 4A).

In operation, the xtal filter 430 may effectively filter out (at leastmost) of high power interference signals which may be introduced intothe reference signal generated using the xtal core 410, particularlyinterference signals that may fall at harmonics positions, as furtherillustrated in FIG. 4B, which shows frequency charts for an example usescenario in the crystal (xtal) oscillator of FIG. 4A.

For example, as illustrated in FIG. 4A, the signal being fed into thextal buffer 420 from the xtal core 410, after processing via the xtalfilter 430, at point A (as marked in FIG. 4A) includes the crystal-basedsignal (at f_xtal) and only minimal (negligible) interference signals atthe harmonics positions (e.g., N1*f_xtal, N2*f_xtal, N3*f_xtal, etc.),as illustrated in frequency chart 411 in FIG. 4B.

As a result, the output signal of the xtal buffer 420 (e.g., squareclock signal), at point B (as marked in FIG. 4A) may comprise mostly (orwholly) the crystal-based signal, with very minimal, if any,interference signals at the xtal oscillator signal's frequency (f_xtal),as well as at certain harmonics positions (e.g., N3*f_xtal, N5*f_xtal,etc.), as illustrated in frequency chart 421 in FIG. 4B.

FIG. 5 illustrates a flowchart of an example process for handlingcrystal (xtal) oscillator with high interference immunity. Shown in FIG.5 is flow chart 500, comprising a plurality of example steps(represented as blocks 502-510), for handling crystal (xtal) oscillatorwith high interference immunity (e.g., electronic arrangement 200 ofFIG. 2), in accordance with the present disclosure.

In start step 502, an electronic system comprising (or utilizing) acrystal oscillator may be configured for operation, such by performingnecessary setup and/or configuration functions.

In step 504, a reference signal may be generated, such as via a crystalcore (e.g., xtal core 410) of the crystal oscillator (e.g., based onresonant frequency of the crystal core). For example, the referencesignal may have a resonant frequency of f_xtal.

In step 506, the generated signals may be processed to mitigate effectsof interference, such as by filtering possible interference signals atharmonic positions based on the frequency of the reference signals(e.g., at positions N1*f_xtal, N2*f_xtal, N3*f_xtal, etc.).

In step 508, post-processing (e.g., buffering and digitization) may beapplied, such as to provide digital periodic signals having particulardesirable frequency.

In step 510, the generated signals may be provided—e.g., for clocking.

Other embodiments of the invention may provide a non-transitory computerreadable medium and/or storage medium, and/or a non-transitory machinereadable medium and/or storage medium, having stored thereon, a machinecode and/or a computer program having at least one code sectionexecutable by a machine and/or a computer, thereby causing the machineand/or computer to perform the processes as described herein.

Accordingly, various embodiments in accordance with the presentinvention may be realized in hardware, software, or a combination ofhardware and software. The present invention may be realized in acentralized fashion in at least one computing system, or in adistributed fashion where different elements are spread across severalinterconnected computing systems. Any kind of computing system or otherapparatus adapted for carrying out the methods described herein issuited. A typical combination of hardware and software may be ageneral-purpose computing system with a program or other code that, whenbeing loaded and executed, controls the computing system such that itcarries out the methods described herein. Another typical implementationmay comprise an application specific integrated circuit or chip.

Various embodiments in accordance with the present invention may also beembedded in a computer program product, which comprises all the featuresenabling the implementation of the methods described herein, and whichwhen loaded in a computer system is able to carry out these methods.Computer program in the present context means any expression, in anylanguage, code or notation, of a set of instructions intended to cause asystem having an information processing capability to perform aparticular function either directly or after either or both of thefollowing: a) conversion to another language, code or notation; b)reproduction in a different material form.

While the present invention has been described with reference to certainembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted withoutdeparting from the scope of the present invention. In addition, manymodifications may be made to adapt a particular situation or material tothe teachings of the present invention without departing from its scope.Therefore, it is intended that the present invention not be limited tothe particular embodiment disclosed, but that the present invention willinclude all embodiments falling within the scope of the appended claims.

1-20. (canceled)
 21. A method comprising: generating reference signalshaving a particular reference frequency that is set or determined basedon characteristics of a source of the reference signals; and processingthe generated reference signals, wherein the processing of the generatedreference signals is based on: other operations and/or componentsassociated with the source of the reference signals; and particularfrequency positions relative to the particular reference frequency. 22.The method of claim 21, wherein processing the generated referencesignals comprises applying filtering based on the particular referencefrequency.
 23. The method of claim 22, wherein the filtering filters outsignals at one or more of the particular relative frequency positions.24. The method of claim 21, wherein processing the generated referencesignals comprises digitizing the generated reference signals, togenerate corresponding digital reference signals.
 25. The method ofclaim 24, comprising generating based on the digitizing of the generatedreference signals, corresponding digital reference signals.
 26. Themethod of claim 21, wherein processing the generated reference signalscomprises buffering.
 27. The method of claim 21, wherein the particularrelative frequency positions comprise harmonics positions of theparticular reference frequency.
 28. A system comprising: a signal sourcethat generates reference signals having a particular reference frequencybased on characteristics of the source of the reference signals; and oneor more processing circuits that process the generated referencesignals, based on: other operations and/or components of the system; andparticular frequency positions relative to the particular referencefrequency.
 29. The system of claim 28, wherein the one or moreprocessing circuits comprise a filtering circuit that applies filteringto the generated reference signals based on the particular referencefrequency.
 30. The system of claim 29, wherein the filtering circuitfilters out signals at one or more of the particular relative frequencypositions.
 31. The system of claim 29, wherein the filtering circuitcomprises a resistor-capacitor (RC) circuit.
 32. The system of claim 28,wherein the one or more processing circuits comprise a buffer circuitthat buffers the generated reference signals during processing of thesignals.
 33. The system of claim 32, wherein the buffer circuitdigitizes the generated reference signals.
 34. The system of claim 33,wherein the buffer circuit generates based on the digitizing of thegenerated reference signals, corresponding digital reference signals.35. The system of claim 28, wherein the source of the reference signalscomprises a crystal oscillator that provides the reference signals. 36.The system of claim 25, wherein the crystal oscillator generates thereference signals based on resonance of a crystal core.
 37. The systemof claim 28, wherein the one or more processing circuits process thegenerated reference signals based on the particular relative frequencypositions being harmonics positions of the particular referencefrequency.
 38. The system of claim 28, comprising one or moretransceiver circuits configured for handling reception and/ortransmissions of radio frequency (RF) signals.
 39. The system of claim38, wherein at least one of the one or more transceiver circuits isdriven based on the generated reference signals.